Wiper arrangement with a rotatable wiper arm in addition to the reciprocating movement

ABSTRACT

A wiper arrangement for windscreen wipers in motor vehicles in which the wiper blade is rotated, depending on the pivoting angle of the wiper arm thus conforming to the curvature of the windscreen. The entire wiper arm rotates to a certain degree as the wiper spindle pivots depending on the pivoting angle. The crank control which is fitted in a control sleeve embracing a spherical cap on the wiper spindle and being rotatable in relation thereto. The control sleeve is controlled by a circumferential control edge on the bearing sleeve of the wiper shaft.

TECHNICAL FIELD

The present invention relates to wiper arrangements, and moreparticularly to wiper arms in which the position of the wiper blade isadjustable in accordance with the curvature of the windscreen to becleaned.

BACKGROUND OF THE INVENTION

The requirement of an angular adjustability of the wiper blade isincreasingly imposed in view of the fact that windscreens morefrequently are designed curved to minimize the air resistancecoefficient of automotive vehicles. To adjust the angular position ofthe wiper blade, a multiplicity of solutions has been offered in which,on the one hand, the wiper blade itself is adjusted with respect to thewiper arm while, on the other hand, one end section of the wiper arm isrotated with respect to the remainder of the mounting section.

DE-OS 3 900 525 teaches to provide a means for fixing the wiper arm tothe wiper spindle which is pivoted along with the wiper spindle, therebyalso causing a reciprocating movement of the remainder of the wiper arm.In addition, the remainder of the wiper arm is rotatably arranged withinthe mounting means, with the remainder of the wiper arm during itsoscillating movement being rotated by a corresponding crank control. Thedisadvantage of this arrangement is that the section of the wiper armassociated to the wiper spindle is divided into two oppositely movableparts requiring enhanced mechanical efforts. Moreover, the prior knownconstruction regarding the rotating movement of the wiper arm permitsonly relatively short force levers.

FR 2 625 715 discloses a wiper arrangement in which the reciprocatingpivotal movement of the wiper arm about the axis of the wiper spindle issuperimposed by an additional reciprocating rotary movement of the wiperarm about the longitudinal axis thereof. The wiper arm is fixed to acontrol part, which by means of another component secured to the wiperspindle, is pivoted about the axis of the wiper spindle and at the sametime is pivotally rotated by moving a control curve about thelongitudinal axis of the wiper arm. The disadvantage of this solutionresides in the bearing points of the control part which are exposed tovery high loads because all forces transferred to the wiper arm travelexclusively through the bearing points (the bearing points are requiredto accommodate all counter-forces of the wiper arm).

SUMMARY OF THE INVENTION

The object of the invention is to provide a simpler wiper arrangement ofthis type and to reduce the number of required components.

This object is fulfilled in that the section of the wiper arm is notdivided into one part only pivotable and another part pivotable androtatable but rather in that the entire wiper arm is not only pivotablebut also rotatable in a direction vertical to the reciprocatingmovement.

In view of the fact that a spherical ring is secured to the wiperspindle, the spherical outer face of which is embraced by a controlsleeve, a relatively large, common bearing surface is formed which isable to withstand relatively high loads. Moreover, the geometry of thisspherical bearings face ensures a reliable control of the wiper armconnected to the control sleeve.

Once the wiper arm is connected to the spherical ring by means of twojournals arranged on the longitudinal axis of the wiper arm and radiallyextending through the control sleeve, a very safe connection isestablished between the wiper spindle and the wiper arms so thatrelatively high torques can be initiated in the pivoting plane of thewiper arm. If one end of a journal is provided in an axial recess of thewiper arm while the other end is arranged in a radial recess of thespherical ring, a relatively easy assembly of the individual componentsis permitted.

To increase the leverage for applying the force required for therotating movement about the longitudinal axis of the wiper arm, it ispreferred that the control disk is formed with a control curve byradially projecting the circumferential edge of the control disk ontothe bearing sleeve for the wiper spindle. The control disk can bearranged at a suitable distance from the longitudinal axis of the wiperarm, with the control disk being united to the bearing sleeve of thewiper spindle such that this component simultaneously performs aplurality of functions. Preferably the edge of the control disk iscircumferentially disposed at a suitable point of the bearing sleevedepending on the desired distance from the axis of rotation of the wiperarm.

In a preferred embodiment of the present invention, the inner face ofthe wiper bearings (associated with the control disk) is designed to beuniform with the control sleeve such that the characteristics of thereciprocating rotary motion of the wiper arm about the longitudinal axisthereof can be adapted to the curvature of the windscreen to the wiped.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of one form of embodiment of the invention.

FIG. 2 is a sectional illustration of another view of the example ofembodiment of FIG. 1.

FIG. 3 is a schematic illustration of a wiper blade attached to a wiperarm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Now, referring to the drawing, FIG. 1 shows a wiper spindle 1 rotating,in a reciprocating way, about a longitudinal or pivot axis 22 of thespindle. The spindle 1 is provided in a bearing sleeve 2 attached by nut4 to a chassis plate 3, thereby being fixed thereagainst. Plugged ontothe wiper spindle 1 is a spherical ring 5 the outer face of which formsa spherical zone. The ring itself, by keying to the spindle and byscrewing through nut 7, is detachably fixed to the spindle. Thespherical face 8 of the spherical ring 5 is embraced by a correspondingconcave inner face 9 of a control sleeve 10 accommodating the wiper-sideend of a wiper arm 11. A wiper blade 6 is disposed at an end of arm 11.The wiper arm 11 includes an accommodating bore 12 embracing the outercylindrical surface of the control sleeve 10. Two journals 13,14radially extending through the accommodating sleeve 10 and protrudinginto suitable axial recesses 15,16 and 17,18, respectively, of the wiperarm 11 (in a manner adjacent the accommodating bore 12) and of thespherical face 8 of the spherical ring 5, respectively, insure that thewiper arm 11 toward the spherical ring 5 and, hence, toward the wiperspindle 1 is locked against rotation about the longitudinal axis 22,thereby causing the wiper arm 11 to espouse, in the direction ofrotation of the axis of rotation 22, the reciprocating movement of thewiper spindle 1.

However, the journal mounting means also permits a rotation of the wiperarm 11 over the spherical ring 5 and, hence, over the wiper spindle 1,about the axis of rotation 23 as shown in phantom in FIG. 4. Under theaction of the cylindrical journal 13,14, during the pivot movement ofthe wiper arm 11 about the axis of rotation 23, the control sleeve 10 issimultaneously pivoted about the said axis. Thus the control sleeve 10in connection with the wiper arm 11 is able to perform a joint limitedrotary movement about the axis of rotation 23. Conversely, this meansthat a rotary movement of the control sleeve 10 about the axis ofrotation 23 at the same time results in a corresponding rotary movementof the wiper arm 11. This limited rotary movement is caused by acircumferential control edge 26 on the upper end of the bearing sleeve2. The circular outer edge 27 of the circumferential edge 26 iseccentric over the circular circumference 28 of the spindle 1. In thedrawing, the section is so selected that the respectively visible pointof intersection between the edge 27 and the plane of the drawing is atthe same distance from the longitudinal axis 22. In FIG. 2, these arethe two points M and N. However, FIG. 2 conveys that the correspondingpoints of intersection P, Q in case of a section in a direction verticalto the viewer's plane along the pivot axis 22, respectively are at adifferent distance from the pivot axis 22. This means that in a pivotmovement of the control sleeve 10 along with the wiper spindle 1, theopen end 19 at the same time is rotated, in a reciprocating way, by asmall angular area about the axis of rotation 23 as shown in FIG. 4.

Hence, the inner face of the open end 19 of the control sleeve 10 inconjunction with the outer edge 27 acts as a control crank to generatethe rotary movement of the control sleeve 10 and, hence, of the wiperarm 11. The crank control can, of course, also be so designed that thewiper am 11 performs a rotary movement less steadily dependent on thereciprocating movement of the spindle 1. For this purpose, only thecontour of the outer edge 27 will have to be changed accordingly.Another advantageous alternative resides in that the contour of theouter edge 27 over the pivot axis 22 is formed centrally while theassociated inner face 20 at the open end of the control sleeve 10 isconfigured so eccentrically that the control sleeve, depending on thepivoting position of the spindle 1, is given the desired rotaryposition. The advantage involved therewith, in particular, resides inthat an otherwise unchanged wiper arrangement by correspondinglydesigned control sleeves 10 can be easily adapted to the curvature ofthe respective type of windscreen with no need to change the design ofthe spindle 1 or of the stationary bearing sleeve 2.

The invention involves the additional advantage that wiper arm 11,control sleeve 10 and spherical ring 5 can be premanufactured, storedand handled as a unit, thereby enabling the otherwise identical wiperarrangement to be easily adapted to various types of windscreens. Toprotect the wiper system against contamination and against injuries ofoperators by otherwise unprotected sharp edges, a protective cap 21 isusually plugged onto the wiper arm, which protective cap performstherewith both the reciprocating and rotary movements.

We claim:
 1. A wiper system comprising:a wiper arm rotatably fixed to awiper spindle for reciprocating rotary movement therewith about aspindle axis of the wiper spindle and the wiper arm having alongitudinal axis, a control sleeve radially disposed between the wiperspindle and the wiper arm and is rotatably fixed to the wiper arm forunitary rotation therewith, a spherical ring fixed to the wiper spindlehaving a spherical face which is embraced by a concave inner surface ofthe control sleeve and the control sleeve being pivotable along with thewiper arm about the longitudinal axis of the wiper arm, with the controlsleeve being supported on a control edge of a stationary member fixed toa chassis plate by a force applied in a direction transverse to thespindle axis (A) and transverse to the longitudinal axis of the wiperarm, and a wiper blade connected to the wiper arm wherein the controlsleeve is pivoted about the longitudinal axis as a function of itsrotative position relative to the control edge, thereby causing thewiper arm to pivot therewith about the longitudinal axis as a functionof rotary movement of the wiper arm about the spindle axis.
 2. A wiperarrangement according to claim 1, wherein the wiper arm is connected tothe spherical ring by means of two journals aligned with thelongitudinal axis of the wiper arm and radially extending through thecontrol sleeve and into the spherical ring.
 3. A wiper arrangementaccording to claim 2, wherein the journals each have one end in an axialrecess of the wiper arm and another end within a radial recess of thespherical ring.
 4. A wiper arrangement according to claim 3, wherein thecontrol edge comprises a radially projecting circumferential edge on abearing sleeve for the wiper spindle.
 5. A wiper arrangement accordingto claim 4, wherein the bearing sleeve is of a circular design and isconcentric to the spindle axis and an inner face of the control sleeveassociated with the bearing sleeve is of an eccentric configuration suchthat it performs the function of the control edge.